William h



(No Model.)

W. H. SAWYER.

MANUFACTURE 01- DRILLS. No. 361,452. Patented Apr. 19, 1887 Mai , for dies for drawing fine wire.

UNITED. STATES PATENT OFFICE.

\VILLIAM H. SAWVYER OF PROVIDENCE, RHODE ISLAND.

MANUFACTURE oF DRILLS.

SPECIFICATION forming part of Letters Patent No. 361,452, dated April 19, 1887.

Application filed September 30, 1884. Serial No. 144,376. (No model.)

T 0 all whom it may concern..- e

Be' it known that I, WILLIA1\I H. SAWYER, a citizen of the United States, residing at Providence, in the county of Providence and State of Rhode Island, have invented certain new and useful Improvements in the Mannfacture of'Drills and Iteamers, of which the following is a specification,reference being bad therein to the accompanying drawings. V

vMy invention relates to tools intended for boring or reaming out die-holes in hard precious stones and other hard substances used As the holes in such dies are frequently less than one-thousandth of an inch in diameter,it will be readily understood that the drill-point required to form such' a hole, or to ream it out after being formed, must be extremely delicate and liable to break. Such tools have heretofore been made of hard steel with stout shanks, having ends reduced to short needle-like points.

When one of such points breaks off, as they frequently do in. use, the work of again properly reducing the shank and shaping and fin-' i'shing the point is extremely tedious .and involves a great expenditure of time. The newlyformed point is not infrequently broken off in finishing and polishing before even being used.

It is the object of my invention to obviate the very great expenditure of time and labor heretofore required in the manufacture of tools of the kind referred to; and to this end, instead of reducing a. comparatively large shank-piece to form the drill-point, I take a fine piece of platina wire of the required size and cover it thickly with copper by electrodeposition, the diameter given it by the deposit of copper depending upon the size of the drill-stock socket in which it is to be secured, or upon conveniencein handling. The plated or covered wire is the equivalent of the old shank-piece, and to form the drill-point I simply insert one end, say one-sixteenth to one-fourth of an inch, in some strong acid-- nitric acid, for instance-which will eat away the copper without affecting'the platina core. A fine short point is thus left projecting from a shank of such size and strength as to be not easily twisted, broken, or bent, and this point may be used efficiently for drilling or reaming out holes in the hardest substances. When by accident the point is broken off or is worn down too short, a new point maybe formed by simply again inserting the shank in the acid until the copper is dissolved away to uncover a sufficient length of the platina wire. The size of the platina wire used will of course be governed by the character of the work to be done.

I do not confine myself to platina wire with a copper covering, as I may use any other suitable metal which may be deposited on the wire and dissolved away by an acid without affecting the platina, and I may use any other sufficiently hard metal for the core instead of platina.

In the accompanying drawings, Figure 1 is a view of a drill or reamer constructed according to my invention. Fig. 2 is a longitudinal section of the same, and Fig. 3 is a side eleva tion of a convenient apparatus for supporting the shank while one end is subjected to the action of the acid.

In Figs. 1 and 2 the letter A indicates the hard central wire, preferably platina; and B, the covering of softer metal, which may be dissolved by asuitable acid tolleave a projecting point, a, the tip of which may, if desired, be given any special shape by means of filing. The surrounding metal may be also tapered with a file, if necessary.

In Fig. 3, O is astandard rising from a base, D, and having an adjustable arm, E, carrying at its outer end a collar, F, provided with a clamping-screw, g. The drill or reamer shank may be arranged in the collar and adjusted so that its lower end will be immersed a proper distance in the acid held by a suitable vessel, as at H, the acid being, indicated in dotted lines. The apparatus shown is convenient; but its use is not absolutely necessary, as the shank may be dipped in the acid by hand.

What I claim isf 1. The herein-described improvement in the method of making drills and reamers, the same consisting in covering a metallic wire with a 2. A drill consisting of a hard-metal core wire covered by an eleetro-deposit of softer metahexcept a projecting portion to form the drillpoint, substantially as described.

5 3. A drill consisting of a fine platina wire covered with an releetro-deposit of copper, except a projecting portion which forms the drillpoint.

4. A drill consisting of a hard-metal core to or wire covered by an electro deposit ofsofter metal, whereby the said softer metal can be readily removed to provide a projecting portion of the metal core to form the drill-point, substantially as specified.

In testimony whereof I affix my signature in 1 presence of two witnesses.

\VILLTAM II. SrUVYER. Vitn esses:

GILMAN E. J OPP, W. A. HATHAWAY. 

